tuProlog
- A Java-based light-weight Prolog for Internet applications and infrastructures, developed at DEIS - Universitá di Bologna. Released under GNU Library or Lesser General Public License.
- http://sourceforge.net/projects/tuprolog

JLog
- A Prolog interpreter, written in Java, that is well suited for educational purposes. It works as both an application and as an applet.
- http://jlogic.sourceforge.net/

W-Prolog
- This simple interpreter for a Prolog-like language is written in Java. Although not fast the implementation is extremely portable and can be run as an applet under Java-capable web browsers.
- http://goanna.cs.rmit.edu.au/~winikoff/wp/

Prolog+CG
- Java implementation of Prolog plus the Conceptual Graphs of John Sowa. Object oriented extensions also included. [Open source, LGPL]
- http://prologpluscg.sourceforge.net

MINERVA
- Implementation of ISO Prolog in 100% Java. Extensible with any Java class. Callable as servlet, applet, standalone, or Java class library. Includes XML parser and generator. [Commercial]
- http://www.ifcomputer.com/MINERVA/

jProlog
- Experimental Prolog to Java compiler, running on JDK 1.0.2 and higher.
- http://www.cs.kuleuven.ac.be/~bmd/PrologInJava/

JIP
- Java Internet Prolog is a Prolog Java-compatible interpreter. JDK1.1- and Edinburgh Prolog-compliant this Prolog version allows code written in Prolog to be run in any Java applet or application and Java methods to be called in any Prolog code.
- http://www.ugosweb.com/jiprolog/

Jinni 2000 (Java INference Engine and Networked Interactor)
- A fast multi-threaded, networking and GUI enabled Prolog compiler, extensible through a Reflection based Java interface.
- http://www.binnetcorp.com/Jinni/

JavaLog
- Experimental Prolog interpreter in Java, mixing Logic and OO paradigms.
- http://javalog.sourceforge.net/